Case #468 – May, 2018

The object shown in Figures A–C was found in a stool specimen collected in SAF (sodium acetate-acetic acid- formalin) from a 43-year-old woman born and raised in Manitoba, Canada with no recent travel reported. Estimated length of the object was 8 millimeters. What is your diagnosis? Based on what criteria?

(This case and images were kindly provided by the Cadham Provincial Public Health Laboratory, Winnipeg, MB)

Figure A

Figure B

Figure C

This was a case of enterobiasis caused by Enterobius vermicularis (pinworm). Diagnostic morphologic features presented in this case were:

robust worm with cephalic inflations (Figure B).
long, slender tapered tail (Figure C) is a diagnostic feature of female worms of the species.
size of the worm was within that for female pinworms.

A follow-up inquiry to the provider of this case asking if eggs were observed in utero revealed that they were not; however the other features observed were still sufficient to make the diagnosis.

More on enterobiasis: https://www.cdc.gov/dpdx/enterobiasis/index.html

Images presented in the dpdx case studies are from specimens submitted for diagnosis or archiving. On rare occasions, clinical histories given may be partly fictitious.